Herbicides sprayed over a field area combat unwanted plants (“weeds”) mixed within wanted crops. To optimize use, the field area may be treated with a varying dose of the herbicide based on the weed percentage (for instance the affected area percentage based on the total area considered).
The document DE 689 12 126 T2 describes the practice of detecting the reflectivity of a target area for particular bands of the electromagnetic spectrum, the relevant recorded values being compared with values in a particular look-up table. On the one hand, the detection of a reflectivity is susceptible to errors in the case of strong changing outside light irradiation. On the other hand, the storage of look-up tables and the comparison with the latter require a large amount of computational effort which increases with the quality of the adaptation to light conditions. In addition, the values in said look-up tables must also take into account the respective growth state of the plants, which additionally drives up their range.